Related Articles

Aphids, mites, mealybugs and other soft-bodied insects feed on tomato (Solanum lycopersicum) leaves and stems by sucking out the sap from the foliage. Although a small population of pests won't cause excessive damage from feeding, they can spread viral and bacterial diseases to your otherwise healthy tomatoes. Homemade insecticidal soaps give you a low-cost control method that doesn't harm plants and animals, making it safer than more chemical-laden pesticides. When made and used properly, the soap spray doesn't harm your tomatoes but it does eradicate the pests.

1

Fill a large spray bottle with 1 quart of tap water. Add 1/2 tablespoon of vegetable oil to the water.

2

Add 1/2 to 3/4 tablespoon of liquid dishwashing soap or baby shampoo to the water. Do not use soap made for automatic dishwashers, and only use mild fragrance-free, nondetergent soaps that don't contain antibacterial ingredients.

3

Screw the cap on the spray bottle and shake it gently to combine all ingredients. Label the spray bottle with the contents.

4

Spray the affected portions of the tomato plant with the insecticidal soap in the early morning or on a cloudy day. Most pests congregate on the undersides of the leaves. Reapply the soap every five to seven days until the pests are gone.

Things You Will Need

Spray bottle

Vegetable oil

Mild liquid soap

Tip

Mix 1/2 tablespoon of baking soda into the spray if the tomatoes are suffering from mildew or other fungal problems.

Warnings

Some soap products may damage tomato plants. Test the spray on two or three leaves, and then wait three days to ensure no damage occurs before proceeding with treatment on the entire plant or plants.

Do not apply the spray during hot weather or in direct sunlight. Avoid using soap sprays on plants with naturally hairy or waxy leaves.

About the Author

Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.